Improvement in piston-packings



PATENT JOHN M. CLAY, OF LANCASTER, PENNSYLVANIA.

IMPROVEMENT IN Pi$TONPACKlNG$.

Specification forming part of Letters Patent No. 133,519, dated December 3, 1872.

1'0 all'whom it may concern:

Be it known that I, JOHN M. CLAY, of Lancaster, in the county of Lancaster and State of Pennsylvania, have invented certain Improvements in the Adjustment and Expansion' of Piston-Heads for Steam-Cylinders, of which the following is a specification:

This invention relates to the interior arrangement of the piston-head, and manner of expanding the rings and centralizing the hearing of the piston-rod.

The accompanying drawing illustrates my improvements in place of an ordinary pistonhead, with its open rings, follower, 850., also shown.

Figure 1 is a top view of the interior arrangement with the cap or follower removed. Fig. 2 is a side elevation with portions of the rings removed or broken out to show the key or segmental flange and plug in place. Figs. 3 are detached portions shown in perspective.

The piston-rod S and head, composed of cut or open rings 0 C and D, with the hub G and radiating arms, and base B, and cap or follower A, are not novel, and require no further description. I show ahub, G, with three radiating arms. These may be increased according to the size or diameter of the cylinder; or on a small piston a central screw may hold the cap or follower A in place. On the lower side of the hub G I show a'fiat face, g, out for a screw, 71,, which screw is provided with a head, I, having a nipple centrally on its outer face, marked v1, rounded so that it may turn, but be confined in the slot R of the key-plug K, against which it acts. There is a jam-nut, H, to hold the adjustment when made. In horizontal cylinders, the lower portion of the piston-head is inclined to wear off faster by the gravitating force added to the friction hence this screw is made to enter the thread cut in the hub G, under the center of the piston-rod, the screw supporting the same, so that when worn below it is easily again centralized and adjusted from time to time. The expansion of the rings is effected by a new device, which consists of the plug or spring-box K, having an open shouldered central cell, 1;. Upon the bottom or shoulders of this cell there rests a stout spiral spring, higher than the plug. The whole sits over or embraces a screw shaft or stud, O, afiixed to the bed-plate B. This plug K has aflange, L, curved with the radius of the inner ring D, (supplying the segment cut out,) made wedgeshaped, of the thickness of the ring, but so much lower as to allow, say, one-third wedgrug-space. the section out out of the inner ring, being alike bevel, so as to sit in the ring above like a key-stone. The wedgin g for expanding the rings is performed by means of a nut, IT, screwed down upon the top of the spring in the cell of the plug. This spring rests upon the shoulder or flange of the cell, and presses the plug K with its raised wedge-flange or segment L down, and consequently expands the inner ring D, which, at the same time, ex-

pands the outer rings (1.0. There is also a f j am-n ut, M, to hold the adjustment when made.

Fig. 1 shows the piston S in thecenter of the hub G, the screw-head I with its nipple i fitting in the groove R of the key-plug K, and its flange wedge or key L with the nuts and j am-nuts H MN. In Fig. 2 the cell and spiral spring are shown, which arrangement for contralizing the piston-rod and expanding the rings for the purpose of adjusting pistonheads comprises my invention, and which I believe to be novel; the utility is fairly tested and proved. I am aware that various devices are employed to the same end, but they differ substantially in the construction and arrangement, and are more complicated or less efficient.

What I claim as my invention, and desire set forth.

' JOHN M. CLAY. Witnesses:

. JNo. M. AMWEG,

J noon STAU'FFER.

This flange or segment fits into 

